Restore Peak Performance to Your GM Vehicle
If you’re dealing with a frustrating check engine light, poor fuel economy, stalling, or a no-start condition in your GM truck, van, or SUV, a failing Powertrain Control Module (PCM) is often the culprit. As the brain of your vehicle’s engine, a faulty PCM can cause a wide range of baffling issues. This genuine, used OEM Engine Control Module, part number 09355699, is the reliable and cost-effective solution you’ve been searching for. Forget the high costs and scheduling hassles of the dealership. We take the complexity out of the repair by programming this module specifically for your vehicle using your VIN.
From the Diagnostic Bay: The Intermittent No-Start Nightmare
I remember a ’99 Suburban that came into my shop with an issue that was driving the owner crazy. It would start and run perfectly for weeks, then suddenly refuse to start. No crank, no click, nothing. After a few hours, it would fire right up as if nothing happened. We checked the battery, starter, and ignition switch—all were fine. The scanner showed no communication with the PCM during the no-start events. After swapping in a known-good test unit, the problem vanished. The original PCM had an internal intermittent failure, a classic sign of aging electronics. This is why a quality-tested, correctly programmed replacement 1998 Envoy PCM is so critical for a lasting repair.
Is Your GM Vehicle Showing These Symptoms?
- ✔ Persistent Check Engine Light (CEL)
- ✔ Diagnostic Trouble Codes (DTCs) related to internal module failure, such as P0601, P0602, or P0606
- ✔ Vehicle won’t start or is very hard to start
- ✔ Rough or erratic engine idle
- ✔ Unexplained drops in fuel efficiency
- ✔ Hesitation or stumbling during acceleration
- ✔ Automatic transmission shifting poorly or erratically
- ✔ Failure to pass an emissions test
A Straightforward Guide to Swapping Your PCM
Installing your pre-programmed module is a job most DIYers can handle with basic tools. Our VIN-specific programming makes this a much simpler process.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work.
- Locate the PCM: On most of these GM models, the PCM is located in the engine compartment, often on the driver’s or passenger’s side fender well or near the battery. Refer to your vehicle’s service manual for the exact location.
- Disconnect Connectors: Carefully unclip the wiring harness connectors from the old PCM. These connectors have locking tabs that need to be released before they can be pulled away. Avoid forcing them.
- Remove the Old Module: Unbolt the old PCM from its mounting bracket and remove it from the vehicle.
- Install the New Module: Mount your new, pre-programmed 1998 Envoy PCM in the same location and secure it with the original bolts.
- Reconnect Everything: Firmly plug the wiring harness connectors into the new module until they click into place. Reconnect the negative battery terminal.
- Perform Security Relearn (If Necessary): In many cases, you will need to perform a simple security relearn procedure to sync the new PCM with your vehicle’s anti-theft system. This typically involves turning the key to the ‘ON’ position for 10-15 minutes. We will provide specific instructions if required for your vehicle.
Verified Compatibility for These GM Models
This module is a direct replacement for service number 09355699 and is interchangeable with part numbers 16266645, 16250279, 16258815, and 09366810. It is a guaranteed fit for the following vehicles with matching ID 09355699:
- 1998-1999 Chevrolet & GMC C/K 1500, 2500, 3500 Pickups (Gasoline)
- 1998-1999 Chevrolet Express & GMC Savana 1500, 2500, 3500 Vans (Gasoline)
- 1998-1999 Chevrolet Tahoe & GMC Yukon (Gasoline)
- 1998-1999 Chevrolet & GMC Suburban 1500, 2500 (Gasoline)
- 1998 Chevrolet S10 & GMC Sonoma (4.3L V6)
- 1998 Chevrolet Blazer & GMC Jimmy (4.3L V6)
- 1998 Chevrolet Astro & GMC Safari (4.3L V6)
- 1998 Oldsmobile Bravada (4.3L V6)
- 1998 GMC Envoy (4.3L V6)
- 1999 Cadillac Escalade
- 1998 Isuzu Hombre (4.3L V6)
Note: It is crucial to match the service number from your original PCM. If you are unsure, please contact us with your VIN before ordering. This is the best way to ensure you receive the correct, fully compatible 1998 Envoy PCM.